Mexican Dwarf Crayfish

Cambarellus patzcuarensis

Animalia›Arthropoda›Malacostraca›Decapoda›Cambaridae

📍 Mexico

The base species of the popular CPO crayfish, native to Lake Pátzcuaro in Mexico, reaching about 1.6 inches with a wild-type mottled brown to grey coloration. It is one of the smallest and most peaceful crayfish in the hobby, safe in community tanks with most small fish, and easy to breed in soft to moderately hard, slightly alkaline water.

Size1.6"

Min Tank10g

peaceful

Zonebottom

Care Guide

Diet

Mexican Dwarf Crayfish are omnivorous scavengers that consume algae, decaying plant matter, and small organisms. Feed high-quality sinking pellets or specialized crayfish food 2-3 times weekly, supplemented with blanched vegetables (zucchini, spinach) and occasional frozen foods like bloodworms or brine shrimp. They will also forage on leftover fish food and biofilm in the tank.

Behavior

These crayfish are nocturnal and spend most of the day hiding under rocks, plants, or driftwood, becoming more active at night. They are peaceful and solitary, rarely aggressive toward tank mates, though they may occasionally scavenge dead fish or molt in open areas. Males may display minor territorial behavior toward each other, but females are generally more tolerant of conspecifics.

Breeding

Breeding in captivity is moderately easy and occurs readily in established tanks with soft to moderately hard, slightly alkaline water. Females produce small clutches of 20-30 eggs and exhibit maternal care, fanning and protecting the eggs under their abdomen for 3-4 weeks. Juveniles are tiny and require infusoria or liquid fry food initially before graduating to crushed pellets.

Tank Mates

Otocinclus

Peaceful algae eaters with identical water requirements and non-aggressive behavior

excellent

Emerald Dwarf Rasbora

Small, peaceful fish that occupy mid-water zones and won't compete with bottom-dwelling crayfish

excellent

Red Cherry Shrimp

Similar water parameters; crayfish may occasionally hunt shrimplets but adults coexist peacefully

good

Anubias Nana

Hardy plant that provides shelter and won't be uprooted by crayfish burrowing

excellent

Guppy

Small, peaceful fish; crayfish are unlikely to prey on adults but may hunt fry

good

Ramshorn Snail

Peaceful detritivores that share similar ecological roles without direct conflict

good

Common Diseases

Shell Rot (Bacterial Infection)

Symptoms

Soft spots, discoloration, or pitting on the exoskeleton; lethargy and loss of appetite

Treatment

Improve water quality with frequent partial water changes, remove decaying food promptly, and maintain proper pH and hardness. Antibacterial treatments are rarely necessary if husbandry is corrected

Molting Problems

Symptoms

Inability to shed exoskeleton, incomplete molts, or death shortly after molting

Treatment

Ensure adequate calcium and minerals in the water through proper diet and mineral supplements. Maintain stable water parameters and avoid sudden temperature fluctuations

Parasitic Infections (Fungus/Mold)

Symptoms

White or fuzzy growth on body or appendages, particularly around joints and gills

Treatment

Increase water changes, improve aeration, and remove affected individuals to a quarantine tank. Salt baths (1 tablespoon per gallon for 15 minutes) can help; avoid copper-based treatments